Process for flameproofing cellulosic textile fabrics and product obtained thereby

ABSTRACT

THE PRESENT INVENTION RELATES TO A COMPOSITION OF MATTER, SUITABLE FOR FLAMERPROOFING TEXTILE FABRICS, CONSISTING OF AN AZIRIDINYL PHOSPHINE OXIDE OR SULFIDE AND A HALOGEN SUBSTITUTED ALCOHOL OR PHENOL WHICH, WHEN HEATED, WILL COPOLYMERIZE AND REACT WITH THE HYDROXYL OR NITROGEN HYDROGEN OF THE NATURAL OR SYNTHETIC FIBER OF A TEXTILE MATERIAL. THE INVENTION ALSO RELATES TO THE METHOD FOR APPLYING THE COMPOSITION TO THE TEXTILE MATERIAL TO IMPART SAID FLAMEPROOFING CHARACTERISTICS TO THE SO-TREATED TEXTILE MATERIAL.

United States Patent Ofice 3,676,054 PROCESS FOR FLAMEPROOFINGCELLULOSIC TEXTILE FABRICS AND PRODUCT OBTAINED THEREBY Richard H. Symm,Lake Jackson, Tex., assignor to The Dow Chemical Company, Midland, Mich.No Drawing. Filed Mar. 9, 1970, Ser. No. 17,975 Int. Cl. C09k 3/28; D06m13/44, 13/48 US. Cl. 8--116.2 6 Claims ABSTRACT OF THE DISCLOSURE Thepresent invention relates to a composition of matter, suitable forfiameproofing textile fabrics, consisting of an aziridinyl phosphineoxide or sulfide and a halogen substituted alcohol or phenol which, whenheated, will copolymerize and react with the hydroxyl or nitrogen hydrogen of the natural or synthetic fiber of a textile material. Theinvention also relates to the method for applying the composition to thetextile material to impart said flameproofing characteristics to theso-treated textile material.

BACKGROUND OF THE INVENTION Flameproofing of textile materials has beena goal of the industry for many years. Originally, inorganic chemicalswere employed to impregnate the textile materials. The major drawbacksof the use of these chemicals was that large quantities were required toobtain even limited success and the textile material was substantiallyunwashable because the inorganic chemical was soluble in the wash water.Further, the large quantities of chemicals necessarily employed imparteda harshness to the fabric. The Southern Regional Research Laboratory ofthe United States Department of Agriculture has disclosed a new familyof organic nitrogen and phosphorus containing compounds, aziridinylphosphine oxides and sulfides, which are employed to impart a degree offlameproofing to textile fabrics. The compounds, compositions andtechniques employed are fully disclosed in U.S. patents, representativeof which are numbers 2,870,042; 2,886,539; 2,912,412 and 2,915,480. Theprincipal problem encountered in employing the compounds of thesepatents is the necessity to use large quantities of the chemicals Whichimparts a harsh hand to the textile. Another disadvantage of their useis that the process results in a product not as durable as is desiredand the chemicals can be washed out of the garment after severallaunderings in harsh soaps. A further disadvantage of the known art isthat these compounds, which are ordinarily applied from aqueous systems,are unstable in water such that polymerization reactions between theaziridinyl groups and the active hydrogens of the co-reactants, e.g.alcohols, amides, acids, etc. are enhanced.

It is therefore an object of the present invention to provide acomposition of matter which can be employed in smaller quantities thanheretofore employed to obtain initial flameproofing properties and whichresultant chemical polymer will remain in and attached to the textilefor longer periods of time than those previously employed.

Another object of the present invention is to provide a more stablesystem from which to apply the flameproofing chemicals by the use ofnon-flammable, halogenated solvents.

A further object of the present invention is to provide a process forapplying the chemical reactants to the textile in a manner such thatduring the polymerization the polymer will become intimately associatedwith the fiber of the textile material.

3,676,054 Patented July 11, 1972 These and other objects will becomeapparent to those skilled in the art from the following description andclaims.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the presentinvention an aziridinyl phosphine oxide or sulfide is copolymerized witha halogen substituted hydroxyl compound while each reactant isintimately in contact with the other and with the fibers of an organictextile material. The resulting product, which is a copolymer of theaziridinyl compound and the halogen substituted hydroxyl compoundcombined with the textile fibers, is a flameproof textile material. Thereactants are applied to the textile material from a halogenatedhydrocarbon solvent to ensure proper distribution into the fiberstructure of the textile material. After removal of the solvent, thereactants and textile material are heated to between about and 200 C.for up to about five minutes to cause polymerization of the reactantsand reaction between the aziridinyl reactant and/or polymer with thefiber of the textile material.

According to the present invention satisfactory flame retardantproperties can be achieved with textile fabrics by impregnating thetextile fabric with an aziridinyl phosphine oxide or sulfide and ahalogenated alcohol or phenol dissolved or suspended in a chlorinatedsolvent, removing the chlorinated solvent and polymerizing by heatingthe aziridinyl phosphine compound and halogen substituted hydroxylcompound in the presence of the textile fibers which simultaneouslybinds the polymer directly to the fiber. In practice the application tothe fibers can be made from a single solution of both reactants, oralternatively the aziridinyl and halogen containing compounds can beapplied consecutively as, for example, by spraying on separatesolutions. Applying both reactants from the same solution can beaccomplished by spraying or dipping.

Good results are obtained when the ratio of aziridinyl compound to thehalogenated compound is between about 0.5 to 1 and 10 to 1. Suitablechlorinated solvents are those boiling between about 40 and C. Thesolvent can be removed by air drying, by applying heat or vacuum or byother means known to those skilled in the art. A particularly goodmethod of removing solvent is to vaporize it within a closed chamberwhere it can be condensed and recovered. After the solvent is removed,the textile fabric containing the reactants is cured at between about120 C. and 200 C. for from about 0.5 to about 5 minutes. An especiallydesirable range for conducting the cure is from about C. to C. for atime of about 2-3 minutes. The amount of reactants in the solvent shouldbe sufiicient to permit a weight add-on of at least 5 percent in thefinished textile fiber.

Thus, a method for imparting flame retardance to textiles comprises (1)impregnating by contacting a textile fabric with (a) an aziridinylphosphine oxide or sulfide compound and (b) a hydroxyl-containinghalogenated hydrocarbon compound, wherein these compounds are dissolvedin a halogenated hydrocarbon solvent, (2) removing the solvent, and (3)curing by copolymerizing compounds 6a) and (b) above onto the fabric byheating at a temperature above 120 C.

.Az-iridinyl compounds which have proven satisfactory when used inaccordance with the present invention are those having the generalformula 3 wherein X represents the element oxygen or sulfur and each Rrepresents hydrogen or a lower alkyl radical having from 1 to 4 carbonatoms, and Y represents the group (wherein R is as previously defined),an alkoxy group of from 1 to 13 carbon atoms or an aryloxy group of from6 to 10 carbon atoms.

Thus, one can employ tris( 1aziridinyl)phosphine oxide, tris( 1aziridinyl)phosphine sulfide, tris[1 (2 methyl) aziridinyl] phosphineoxide, tris[1-(2-ethyl) aziridinyl] phosphine sulfide, and the like.

Halogenated hydroxyl compounds which have been found to be satisfactorycO-reactants with the aforedescribed aziridinyl compounds are thebrominated, chlorinated and fiuorinated aliphatic and aromatic alcoholsand phenols such as for example,

1,3-dibromo-2-propanol, 2,3-dibromo-1-propano1, 2,2-bis(bromomethyl)-1,3-propanediol, 3-bromo-2,'Zbis (bromomethyl) l-propanol,3-chloro-2,2-bis(bromomethyl) -1-propanol, 4,4'-isopropylidene bis(2,6-dibromophenol) 2,4,6-tribromophenol,

2,3 ,4,6-tetrach1orophenol, pentachlorophenol,

4,4-isopropylidene bis( 2,6-di chloro phenol 2,4,6-trichlorophenol,

and their fiuorinated analogs.

The halogenated solvents which can be employed in accordance with thepresent invention are the fluorinated, chlorinated, brominated or mixedhalogen hydrocarbons which have boiling points between about 20 C. and160 C. although those having boiling points between about 40 C. and 125C. are preferred. Some of such solvents are: methylene chloride, carbontetrachloride, chloroform, perchloroethylene, trichloroethylene,dichloroethylene, 1,1- and 1,2-dichloroethane, 1,1,1- and1,1,2-trichloroethane, trichlorobromomethane, trichlorofluoromethane,mono-, diand tri-chloropropanes and propenes, and tetrachloroethanes.Advantageously, curing can be conducted simultaneously with removal ofthe solvent when removing solvents at temperatures above 120 C.

DETAILED DESCRIPTION OF INVENTION Example 1 A sample of 5.8 oZ./sq. yd.cotton sateen cloth was conditioned at 75 F. and 65% relative humidity,weighed, and then soaked for five minutes in a solution of1,1,l-trichloroethane containing 22% by weight, based on the totalWeight of the solution, of tris(1-azin'dinyl) phosphine oxide and 5.5%by weight of 3-bromo-2,2-bis (brornomethyl)-1- propanol. The sample wasremoved from the solution and passed through squeeze rollers to removeexcess solution. Thereafter the sample was air dried for 10 minutes andthen cured in an oven maintained at 160 C. for 2 minutes. The sampleafter curing was conditioned for 16 hours at 75 F. and 65% relativehumidity and Weighed. The weight add-on of chemicals was 12.9%. Thesample was then washed for 2 minutes in a warm solution of TIDE brand ofdetergent, rinsed in warm water and dried in an electric home drier.

The vertical flame retardance test AATCC Method 34-1966, Fire Resistanceof Textile Fabrics, was conducted using the sample prepared above. Theaverage char length of the sample treated as set forth above accordingto the present invention was 4 /2 inches.

4 After twenty washings, each done in accordance with AATCC Method88A-l961T, III wash, C dry, the sample had an average char length of 5inches.

In a series of similar tests different reactants, employed at variousratios and weight add-ons, were used. The results are set forth in TableI.

TABLE I Launderings 0 10 20 Wt. ratio Percent APO l to total Ave.vertical Brominated reactant coreactant add-on char lengths (inches) 1.0:1. 5 26. 8 4 2,2-bis(brornomethyl) 0 3 1 3. i 1 1. 0: 0. 5 18. 1 4% 10:0.25 15.4 8% 11. 3 3% 8. 9 4% 3-bromo-%-2,1bis(bro- I t -1- 2 moms ypropano 10- 9 9.3 5% iii 1,3-dibromo r0 anol p p 16.5 3 14. 5 9% 35. 75% 31.4 47; 1116. 0 4% 4,4-isopropy1idene-bis 1 2 ig (2,6dibromophenol)1g 1 14.0 5 l2. 2 6% 12.0 6 10.3 4% 10. 6 4% 26. 3 3% 13. 9 4% 31. 1 3%20% 3;; 2 4 6-t 3 ribromophenol 1a 8 2 16.4 4% 9. 9 4% 13. 4 3% 10. 9 3%1 APO=Tris(1-aziridinyl) phosphine oxide. 9 BE=Burned entirely.

EXAMPLE 2 In another series of experiments cotton sateen (5.8 oz./sq.yd.) was padded 2 dips and 2 nips through a solution consisting of1,1,l-trichloroethane solvent, 10% by weight propylene glycol, 17% byWeight tris(1-aziridinyl) phosphine oxide and 17% by weightpentachlorophenol (86% pentachlorophenol, 10% other chlorophenols and 4%inert material, a technical grade of pentachlorophenol). The wet pickupwas 64%. The weight add-on was 21.5%. The sample was dried in an ovenfor 2 /2 minutes at C., cured at C. for 2% minutes and washed, rinsed,dried, conditioned and tested as in Example 1. The vertical char lengthof the conditioned sample was 3 /2 inches. After five washings thesample had a 5 /2 inch char length. Other samples treated with differentchloro aromatic compounds in the above manner, washed, etc. gave theresults shown in Table II.

1 APO Tris(1-aziridinyl)phosphine oxide. 1 BE =Burued entirely.

I claim: 1. A method for imparting flame retardance to cellulose textilefabrics which comprises (1) impregnating by contacting said fabric withan aziridinyl phosphine oxide compound and a halogenated lower alkanolwherein said halogenated lower alkanol contains at least two halogenatoms and wherein said impregnating compounds are applied from ahalogenated hydrocarbon solvent solution and at a weight ratio of 0.5 to10 aziridinyl phosphine oxide to 1 of halogenated alkanol (2) removingsaid solvent and (3) curing by copolymerizing said compounds onto saidfabric by heating at a temperature of from about 120-200 C.

2. The method of claim 1 wherein the halogenated lower alkanol is abrominated lower alkanol.

3. The method of claim 2 wherein the brominated lower alkanol is2,2-bis(bromomethyl)-1,3-propane diol, 3 bromo 2,2 bis(bromomethyl) 1propanol or 1,3- dibromo-Z-propanol.

4. The method of claim 1 wherein the impregnating compounds are appliedfrom a single solution.

References Cited UNITED STATES PATENTS 2,912,412 11/1959 Reeves et al.117136 X 2,886,538 5/1959 Chance et al. 117-136 X 2,810,701 10/1957Reeves et al 81l6.2 X

GEORGE F. LESMES, Primary Examiner 5 H. WOLMAN, Assistant Examiner US.Cl. X.R.

